The speed (frequency) of electronic systems continues to increase. Today's computers run at speeds in excess of two GHz, and speeds that are an order of magnitude higher are predicted to be available in the next five years. As the speed of these systems increase, the demand on the electronic interconnect at all levels will be increased to a level beyond the capability of today's interconnection technology. The reason for this is that the impedance of the interconnect rapidly increases with frequency due to the geometric constraints of present technologies. Specifically, the impedance of a conductor will increase with frequency due to a physical phenomenon called “skin effect”. Skin effect is the tendency of alternating currents to flow near the surface of a conductor, thus being restricted to a small part of the total sectional area and producing the effect of increasing the impedance. Skin effect is frequency dependent, resulting in most interconnection systems becoming unusable at high frequency due to this increase in impedance.
The skin effect phenomenon can be minimized by greatly reducing the diameter of the conductor. One example of this is known as the “Litzendraht wire” or more commonly the “Litz wire”. A Litz wire is a woven stranded wire conductor comprised of many, separate fine diameter wires that are electrically insulated from one another other. This structure has a large amount of surface area for a given cross sectional area. As a result, the available surface for conduction with increasing frequency reduces much more slowly than with a solid conductor or stranded conductor with un-insulated strands. Although the Litz wire method works well in certain applications, it is costly to implement and has limited use.